Regulator circuit for generators



Oct. 16, 1962 T. A. BYLES REGULATOR CIRCUIT FOR GENERATORS OriginalFiled Dec. 25, 1957 9 E 47 49 39 57 23 T0 Aufo. E/ecfrica/ 5 SysfemTherm/star L 5 zo B5a//asf fig gkjwa 5 T Ba/fery 20b 2 0 43 Thermisfar 5Heaf Sink INVENTOR.

Theodore A By/es W6ZZW Alb s.

3,059,167, Patented Oct. 16, 1962 3,059,167 REGULATGR CIRCUIT FQRGENERATORS Theodore A. Byles, Villa Paris, 111., assignor to Motorola,

, Inc, Chicago, Ill., a corporation of Illinois Continuation ofapplication Ser. No. 704,421, Dec. 23, 1957. This application Apr. 28,1961, Ser. No. 115,590

' 20 Claims. (Cl. 32225) This invention relates to voltage and currentregulators and more particularly to an electronic regulator of the typeadapted to control the current and voltage of a generator in a vehicularelectrical system. The present application is a continuation of myapplication Serial No. 704,421, filed December 23, 1957, now abandoned.

The present day regulator used in vehicles, such as automobiles,commonly employs electromechanical means to limit the current to a valuewhich the generator can safely supply and to limit the voltage output ofthe generator to a value which will not damage the various devicesconnected to the system in the automobile. In this way, the storagebattery usually included in electrical systems of this type can becharged and, for the most part, supplanted when the generator output issufficient to energize various electrical items in the vehicle. Suchprior art regulators have been troublesome in that calibration thereofmay be unstable and the mechanically operated electrical contacts canfail to operate reliably under the varying conditions which areencountered during use of the vehicle. The electronic regulators knownin the past have not been altogether suitable for the use in a vehicleelectrical system where stability requirements are severe and thetemperature operating ranges are great.

Accordingly, it is an object of this invention to provide an electronicvoltage regulator for an automobile electrical system which has improvedstability and reliability over previously known regulators.

Another object is to provide an improved transistorized regulator for anautomobile generator for charging the battery in the electrical system,which regulator requires no moving parts for limiting the current drawnfrom the generator to prevent overload thereof and for limiting thevoltage output of the generator to prevent application of excesspotentials to the automobile electrical accessories.

Another object of the invention is to provide a temperature responsiveelectronic regulator for an automobile electrical system in which theregulated voltage level is increased at lower temperatures in order tomeet the charging requirements of a lead acid storage battery.

Still another object of the invention is to provide a transistorizedvoltage and current regulator which is temperature compensated in orderto overcome temperature sensitivity of present day transistors, theeffects of which may adversely influence regulator operation as it isused in an automobile under variable ambient temperature conditions.

A feature of the invention is the provision of transistor circuits whichare responsive to current and voltage changes and which are adapted tovariably energize a control winding of a generator system with a novelbiasing arrangement for the transistors to reduce the output of thegenerator system when particular output current or voltage is developed.

Another feature is the provision of a voltage divider network forbiasing a current controlled transistor in a regulator which includes aballast tube and load current carrying resistor means for rendering thetransistor responsive to load current change but unresponsive to loadvoltage change.

Another feature is the provision of such a voltage divider network forbiasing a current sensitive control transistor in a regulator whereinthe temperature sensitivity of the transistor is compensated by anegative temperature coeiiicient resistor to minimize adverse effects ofthe temperature change on the regulated value of the current.

A further feature of the invention is the provision of a biasing networkfor a voltage responsive transistor in a regulator wherein a negativetemperature coeiiicient resistor establishes a higher regulated outputvoltage at low temperatures than is established at higher temperaturesin order to optimize the charging voltage for a storage battery.

A still further feature of the invention is the provision of a regulatorfor an automobile battery charging generator wherein reverse currentflow, or battery discharge, into the regulator is controlled by a powerdiode. The diode may also be used in a simple and inexpensive charg ingsystem for the battery.

Further objects, features and the attending advantages of the inventionwill be apparent upon consideration of the following description whentaken in conjunction with the accompanying drawings, in which:

FIG. 1 is a perspective top view of a regulator with the cover removedand constructed in accordance with the present invention;

FIG. 2 is a perspective bottom view of the regulator of FIG. 1; and

FIG. 3 is a schematic diagram of the regulator constructed in accordancewith the invention.

In a particular form of the invention, a control tran sistor is adaptedto be coupled to a control winding of a generator system for regulatingthe generator system output. The conduction of the control transistor isregulated bya transistor responsive to a certain voltage change and atransistor responsive to a certain current change. Control elements ofthe voltage responsive transistor are coupled to a voltage dividernetwork connected to the out put of the generator system and including azener diode and a negative temperature coefficient resistor so that thevoltage responsive transistor conducts when a given generator voltage isreached, corresponding to a breakdown potential of the zener diode, todecrease the conduction of the control transistor and limit the outputvoltage of the generator system. The negative temperature coefficientresistor causes the effective control voltage limit to increase at lowtemperatures thus providing a higher charging voltage for a lead acidstorage battery at low temperatures. The voltage divider may include aballast tube so that the control voltage limit is less sensitive to thevoltage of the generator system. Control elements of the currentresponsive transistor are coupled to a voltage divider network having afurther negative temperature coeflicient resistor and a constantreference potential established by a ballast tube. The currentresponsive transistor is also controlled by a potential varying withload current so that sufficient increase of the current causesconduction of the current responsive transistor and decreased conductionof the control transistor, and thus the control winding current, toreduce generator system output. The negative temperature coeflicientresistor is placed in the voltage divider network to compensate for achange in the conduction characteristics of the current responsivetransistor during a change in ambient temperature. A power diode may beused at the output of the regulator circuit to prevent reverse currentflow from the battery load into the generator system and a switch andtransformer circuit may be included with the diode circuit to provide asimple means of charging the storage battery from the household powerlines through the power diode.

The voltage and current regualtor shown in FIGS. 1 and 2 includes ahousing frame 10 supporting a printed circuit panel 12 which carriessome of the circuit components identified in connection with theexplanation of the circuit of FIG. 3. A suitable enclosing cover (notshown) 3 may be secured to the frame It) to enclose the components shownin FIG. 1. The components exposed from the bottom of frame as shown inFIG. 2 are protected when the unit is mounted against a surface in theengine compartment of an automobile or other vehicle in which the deviceis used. Electrical connection to the device is made through the frame10 which is a reference point or ground for the device and terminals 14,16 and 18 which are respectively connected to the generator systemoutput, or armature; the generator system control winding, or field; andthe load to which the generator supplies power, or the battery which ischarged by the generator system.

In the schematic diagram of FIG. 3 there is shown a direct currentautomobile generator 20, the armature 20a of which has a positiveterminal connected to the terminal 14 and a negative terminal connectedto ground, or the frame of the regulator. A field winding Nb of thegenerator is connected between ground and terminal 16 of the regulator.The output terminal 18 of the regulator is connected to the positiveterminal of an automobile storage battery 22 and also through ignitionswitch 23 of the automobile electrical system. A negative terminal ofbattery 22 is grounded. Current is supplied from the generator 20 tocharge the battery 22 or to energize the auto electrical system byconduction from terminal 14 through resistor 25, switch 27, which isnormally closed, and diode 29 and terminal 18. Diode 29 is poled toprevent reverse conduction or discharge of the battery 22 into theregulator and generator system. The return current path is, of course,provided through ground.

In the regulator circuit, a power transistor 31 has its emitterconnected to lead 33 which extends between resistor 25 and a terminal ofswitch 27. The base electrode of transistor 31 is connected to groundthrough resistor 35. The output electrode, or collector, of transistor31 is connected to terminal 16 and the field 2% of the generator isseries connected in the emitter-collector circuit of the transistor sothat a change in the transistor output current will vary theenergization of the field winding and thus control the output of thegenerator.

Transistor 35 is connected so that it will be conductive when apredetermined voltage limit is reached and when the generator systemoutput voltage exceeds such limit, transistor 35 conducts to controltransistor 31 in a way to reduce the field current to limit thegenerator output voltage. Transistor 39 is sensitive to the generatorsystem output current conducted through lead 33 and between terminals 14and 18, so that an increase beyond a given current level will cause areduction in the output current of transistor 31 and thereby a reductionof the output of generator 20'. The circuit construction and operationto accomplish these results will now be explained.

To provide the necessary biasing voltages for transistors 35 and 39, avoltage divider network is connected between terminal 14 and ground,with a further portion of the network being connected to lead 33. Thenetwork includes a resistor 41 connected between ground and one fixedterminal of a variable resistor 43, the other fixed terminal of resistor43 being connected to a ballast tube 45. The ballast tube 45 is seriesconnected with resistor 47 which is connected to terminal 14. A seriescombination of resistor 49 and thermistor 51 is connected acrossresistor 47 and a further thermistor S3 is connected across resistor 41.The movable arm of variable resistor 43 is connected to a zener oravalanche type diode 55 which is series connected with resistor 57 tolead 33.

The ballast tube 45 is used to maintain a constant current in its seriescircuit throughout a variation of the generator system output voltageover which the regulator operates. Accordingly, reference potentials areavailable in the voltage divider system which are independent ofvariations in the supply voltage existing between terminal 14 andground.

Transistor 35 is connected in a voltage limit responsive network withits emitter connected to lead 33, its base connected to the junction ofdiode 55 and resistor 57 and its collector connected to the base oftransistor 31. Variable resistor 43 is adjusted to provide a bias ondiode 55 such that this diode will reach its critical back bias voltage,or reverse breakdown voltage, when the voltage be tween lead 33 andground has reached a predetermined maximum at which it is desired tolimit the output of the system. At potentials of lead 33 below thedesired maximum allowable voltage transistor 35 is biased to cutoff andwhen the maximum voltage is exceeded the diode 55 commences conductionin a reverse direction and the current flowing through resistor 57establishes a bias on transistor 35 such that it conducts throughresistor 35 thereby reducing the conduction of transistor 31 andreducing the energizing current in field winding 20b so that thegenerator output is reduced. The system then maintains a balance with asmall control voltage existing across resistor 5'7.

it may be noted that if the collector current of transistor 35 tends torise due to junction heating, this would cause a reduction in thegenerator output voltage thereby reducing the emitter bias on transistor35 until equilibrium was reached. Accordingly, the voltage limitercircuit is self-compensating for temperature effects on the transistor35.

In a particular application of the regulator it may be desirable toraise the maximum limit voltage of the system at lower temperatures. Forexample, in a nominal 14 volt automobile electrical system, it may bedesired that the maximum allowable voltage output be 14 volts attemperatures in the neighborhood of F. and a voltage of 15.8 in theregion nearer 0 F. This is in accordance with the optimum chargingvoltages for some lead acid storage batteries used in automobiles.Thermistor 53 in parallel with resistor 41 is used to provide thiseffect. Thermistor 53 has a negative temperature coefficient so that athigher temperatures the voltage applied from the arm of variableresistor 43 to the zener diode is somewhat lower than it is at lowtemperatures. This temperature control voltage is effectively a biaswhich adds to the breakdown voltage of diode 55. Accordingly, thelimiting voltage at which transistor 35 commences conduction is higheras temperature decreases and the regulator circuit therefor compensatesfor the internal resistance of the storage battery as it varies withtemperature. It may also be noted that it is desirable 'to connect theground side of thermistor 53 by means of an eiiective heat conductorcontact with the frame of the regulator unit to prevent a runawaycondition because as thermistor S3 is heated through self-generatedheat, this would otherwise have the tendency to increase the currentthrough this thermistor and continue the heating process.

The current limiter transistor 39 has a base electrode connected to lead33, and a collector electrode connected to the base of transistor 31 andan emitter electrode connected to the junction of thermistor S1 andresistor 49. Accordingly, transistor 39' is biased by the voltage acrossthe combination of resistors 25 and 49. As previously explained, ballasttube 45 maintains an essentially constant current through the voltagedivider network so that the potential drop across resistor 49 does notvary with variation in the output voltage of generator 20. Thecomponents in the biasing voltage divider network, including resistor47, resistor 49 and thermistor S1, together with resistor 25, provide areverse emitter bias for transistor 39 so that it is biased belowcutoff. However, the value of resistor 25 is selected so that as apredetermined current level is reached a potential drop is producedwhich causes conduction of transistor 39 through resistor 35 therebycontrolling the power transistor 31 to cause the reduction in thecurrent through field 20b and thus a reduction in the output ofgenerator 20.

Transistor 39 may also be temperate sensitive and for any given desiredconduction condition of this transistor the necessary bias may be afunction of the temperature of the transistor. Accordingly, thermistor51, having a negative temperature coefficient, in combination withresistor 49, which has a very small value compared to that of thermistor51, provides a bias voltage for the emitter of transistor 39 which is afunction of temperature to compensate for the change in conductioncharacteristics of the transistor. 7

In particular applications of the electronic current and voltage limiterof the present invention it may be desired that the regulated voltage behigher when the limiter commences operation than it is after to minutesof operation. It has been found that warm-up heating of the device incombination with the temperature compensating circuit elements describedabove are sufiicient to cause a small decrease in the voltage at whichlimiter action takes place thus providing this desirable characteristicof the regulator system.

In a particular successful embodiment of the invention the circuitconstants were as follows:

Transistor 31"; 2N176.

Transistors 35, 39 XN13.

Resistor 25 .008 ohm. Resistor 220 ohms. Resistor 41 12 ohms.

Resistor 43 25 ohms.

Ballast tube 45 DT-S 83.

Resistor 47 3.3 ohms.

Resistor 45 1 'ohm. Thermistors 51, 53 40 ohms at 25 C. Diode 55 ZA12(Hoffman Electronics). Battery 22 Nominally 12 volts.

With the particular circuit constructed according to thesespecifications, current limiting could be successfully maintained at 30arnperes and voltage limiting could be maintained at 15.8 volts at 0 F.and at 14.5 volts at 150 F.

As a further refinement of the circuit, switch 27 includes a contact sothat operation of the switch to establish contact 60 will connect thesecondary of transformer between the diode 29 and ground. The primary oftransformer 65 may include a standard line cord plug 67 so thattransformer 65 can supply the proper voltage from the power lines forrectification by diode 29 and charging of battery 22. Obviously othermethods of connecting transformer 65 to the system may be employed. Inthis way, it is possible to use the cutout diode 29 as part of a simplebattery charging circuit when a power outlet is available.

Accordingly, this invention provides a regulator suit able for use in avehicle electrical system wherein a generator supplies charging powerfor a storage battery used in the system. The current and voltagelimiter action of the system described provides change in outputcharacteristics with temperature as may be required by a storage batteryand successfully maintains desired limit voltage and current valuesduring variation in the ambient temperature of the regulator unitthereby compensating for changes in the characteristics of thecomponents used in the system.

I claim:

1. A voltage regulator circuit including in combination a power circuitadapted to be energized with respect to a reference point by anelectrical source to be regulated, an output control circuit includingcontrol means coupled to said power circuit and responsive to a controlpotential for regulating the output voltage of the electrical powersource, a voltage reference circuit including a temperature sensitiveresistor, a zener diode transistor having input electrodes coupledacross said further resistor, said transistor further having an outputelectrode coupled to said control means, the constants of said voltagereference circuit being selected to provide changed conduction of saidtransistor with the output voltage of the power source above apredetermined value for application of the control potential to saidcontrol means, and said temperature sensitive resistor having atemperature coefiicient for biasing said zener diode and causing thechanged conduction of said transistor at higher output voltages as theambient temperature decreases.

2. A voltage regulator circuit including in combination a power circuitadapted to be energized with respect to a reference point by anelectrical source to be regulated, an output control circuit includingcontrol means coupled to said power circuit and responsive to a controlpotential for regulating the output voltage of the electrical powersource, a voltage divider including a temperature sensitive resistorcoupled between the reference point and said power circuit, a zenerdiode and a resistor series coupled in the order named between saidvoltage divider and said power circuit, a transistor having inputelectrodes coupled across said resistor, said transistor further havingan output electrode coupled to said control means, said zener diode andsaid resistor being selected to provide changed conduction of saidtransistor with the output voltage of the power source above apredetermined value for application of the control potential to saidcontrol means, and said temperature sensitive resistor having atemperature coefiicient for biasing said zener diode to cause thechanged conduction of said transistor at higher output voltages as theambient temperature decreases.

3. A voltage regulator for a vehicular electrical system having anelectromechanical source of direct current with a field winding thereinand a load circuit including a chargeable battery, said regulatorincluding in combination, a first conductor to be energized by thesource of direct current, a first terminal for connection to thebattery, switch means for selectively connecting said first conductor tosaid first terminal, a second terminal for connection to the fieldwinding, frame means providing an electrical reference conductor andforming a heat sink for said regulator, an insulated panel supported bysaid frame means for carrying the interconnected components of saidregulator, a first PNP transistor mounted on said frame means and havinga base electrode and further having an emitter electrode connected tosaid first conductor and a collector electrode connected to said secondterminal, a second PNP transistor having an emitter electrode connectedto said first conductor and a collector electrode connected to said baseof said first transistor and further having a base electrode, firstthrough fourth resistor means supported on said panel, means connectingsaid first resistor means between said base electrode of said firsttransistor and said reference conductor, means connecting said secondand third resistor means in series in the order named between saidreference conductor and said first conductor, a zener diode supported bysaid panel, means connecting said zener diode between theinterconnection of said second and third resistor means and said baseelectrode of said second transistor, means connecting said fourthresistor means between said base electrode of said second transistor andsaid first conductor, and a thermistor connected across at least aportion of said second resistor means.

4. A voltage regulator circuit including in combination an input circuitadapted to be energized with respect to a reference point by anelectrical power source to be regulated, an output power circuit adaptedto be coupled to a battery, an output control circuit including controlmeans responsive to a control potential for regulating the outputvoltage of the electrical power source, voltage divider means coupledbetween said input circuit and the reference point, a transistor havinginput electrodes coupled to said voltage divider means and furtherhaving an output electrode coupled to said control means for applying aregulating signal thereto, said voltage divider means including means toprovide changed conduction of said transistor with the output voltageabove a predetermined value for control of said transistor and saidcontrol means, diode means series connected between said output powercircuit and said input circuit and poled to prevent current flow fromthe battery to said regulator circuit, a circuit for supplying analternating current potential and means for applying such alternatingcurrent potential to said diode means for rectification therein andcharging of the battery.

5. A voltage regulator for a vehicular electromechanical source ofdirect current having a field winding and having output terminal meansfor supplying power to an electrical load of a vehicle including astorage battery, said regulator including in combination, first andsecond conductors for connection to the source of direct current, afield terminal for connection to the field winding, a transistor havingan input electrode and further having output electrodes connectedbetween one of said conductors and said field terminal to controlcurrent in the field winding, voltage sensitive switch means connectedto said input electrode to control the conduction of said transistor,said voltage sensitive switch means including a voltage divider circuitconnected across said first and second conductors and including atemperature responsive resistor, said resistor having a temperatureresponse characteristic related to the charging requirement of thebattery at different temperatures.

6. A voltage regulator for a vehicular electromechanical source ofdirect current having a field winding and having output terminal meansfor supplying power to an electrical load of a vehicle including astorage battery, said regulator including in combination, first andsecond conductors for connection to the source of direct current, afield terminal for connection to the field winding, a first transistorhaving a base and further having an emitter connected to said firstconductor and a collector connected to said field terminal to controlthe current in the field winding, a second transistor having a base andfurther having an emitter connected to said first conductor and acollector connected to said base of said first transistor, a firstresistor connected between said collector of said second transistor andsaid second conductor, a second resistor connected between said base andemitter of said second transistor, a voltage divider connected betweensaid first and second conductors, a zener diode connected between saidbase of said second transistor and an intermediate point of said voltagedivider, and a temperature sensitive resistor connected across a portionof said voltage divider, said temperature sensitive resistor having atemperature response characteristic related to the charging requirementof the battery at different temperatures.

7. A voltage regulator for an automotive electromechanical source ofcurrent having a field winding and adapted to charge an automotivestorage battery, said regulator including in combination, a powercircuit comprising a pair of conductors to be energized with directcurrent from the source and to be connected to the battery, a transistorhaving emitter, collector and base electrodes, means connecting saidemitter electrode to a conductor of the power circuit, means forconnecting said collector electrode to the field winding, a voltageresponsive device with input and output terminals, a bias circuit forsaid base electrode including resistor means connected to said outputterminal, means connecting said bias circuit to said power circuit andto said base electrode for reducing the conduction of said transistor toreduce the current in the field winding, a voltage divider connectedacross said conductors and having a point therein connected to saidinput terminal, said voltage divider including a temperature responsiveresistor having a temperature response characteristic related to thecharging requirements of the battery at different temperatures so thatconduction of said transistor is reduced with the production of a highervoltage by the source at low temperatures than at high temperaturesthereby charging the battery at a higher voltage at low temperaturesthan at high temperatures.

8. A voltage regulator system for an automotive electromechanical sourceof direct current having a field winding and adapted to charge anautomotive storage battery, said regulator system including incombination, a power circuit comprising a first conductor and areference conductor to be energized with direct current from the source,a diode series connected with said first conductor for connecting thesame to the battery, said diode being poled to prevent conduction fromthe battery to said first conductor, a first transistor having emitter,collector and base electrodes, means for connecting said emitter andcollector electrodes in series with the field and across said conductorsso that said first transistor supplies the field current, a secondtransistor having input and output electrodes, a bias circuit for saidbase electrode including a circuit connected to said output electrode sothat said second transistor controls the conduction of said firsttransistor for reducing the conduction of said first transistor to lowerthe current in the field winding, a voltage divider connected acrosssaid conductors and having a point therein connected to said inputelectrode, said voltage divider including a temperature responsiveresistor having a temperature response characteristic related to thecharging requirements of the battery at different temperatures so thatconduction of said first transistor is reduced with the production of ahigher voltage by the source at low temperatures than at hightemperatures thereby charging the battery at a higher voltage at lowtemperatures than at high temperatures.

9. An automotive electric system including in combination, anelectromechanical source of direct current having a field winding, astorage battery adapted to be charged by said source of direct current,an auto electrical circuit including an ignition switch connected tosaid storage battery for energization thereby, a power circuitcomprising a reference conductor connected from said source of directcurrent to said battery and a further conductor including an isolationdiode connected between said source of direct current and said battery,and a voltage regulator circuit connected between the referenceconductor and the interconnection of said source of direct current withsaid diode, said regulator including a tramsistor connected to saidfield winding to be conductive therethrough and a voltage sensitiveswitch means connected to said transistor to control the conductionthereof, said voltage sensitive switch means including a voltage dividerconnected across said conductors and including a temperature responsiveresistor having a response characteristic related to the chargingrequirements of said battery at different temperatures.

10. A current regulator circuit including in combination an inputcircuit adapted to be energized with respect to a reference point by anelectrical power source to be regulated, an output power circuit adaptedto be connected to utilization means to be supplied load current, anoutput control circuit including control means responsive to -a controlpotential for regulating the output of the electrical power source,conductor means including resistor means for carrying load currentconnected between said input circuit and .said output power circuit,voltage divider means coupled between said conductor means and thereference point and including temperature compensated means formaintaining substantially constant current therethrough upon variationof the voltage of the power source, a transistor having input electrodesconnected to said voltage divider means and said resistor means andfurther having an output electrode connected to said control means, saidtemperature compensated means being selected to compensate for changesin transistor characteristics with change in overall temperature of saidcurrent regulator circuit, said resistor means providing a voltage forchanging the conduction of said transistor at a given load current forregulation of said control means and application of the controlpotential to said output control circuit.

11. A voltage and current regulator circuit including in combination aninput circuit adapted to be energized with respect to a reference pointby an electrical power source to be regulated, an output power circuitadapted to be connected to utilization means to be supplied load currentat a given output potential, an output control circuit adapted to beconnected to means responsive to a control potential for regulating theoutput of the electrical power source, conductor means includingresistor means for carrying load current connected between said inputcircuit and said output power circuit, a first transistor having outputelectrodes connected between said output control circuit and said outputpower circuit and further having an input electrode, voltage dividermeans coupled between said conductor means and the reference point andincluding means for maintaining substantially constant currenttherethrough as the voltage at said input circuit varies, a secondtransistor having input electrodes connected to said voltage dividermeans and said resistor means and further having an output electrodeconnected to the input electrode of said first transistor, said resistormeans providing a voltage for changed conduction of said secondtransistor above a given load current for control of said firsttransistor and change of the potential at said output control circuit, athird transistor having input electrodes coupled to said voltage dividermeans and further having an output electrode coupled to said inputelectrode of said first transistor, said voltage divider means includingmeans to cause changed conduction of said third transistor with theoutput voltage above the given output potential for control of saidfirst transistor and change of the potential at said output controlcircuit.

12. A voltage and current regulator circuit including in combination aninput circuit adapted to be energized with respect to a reference pointby an electrical power source to be regulated, an output power circuitadapted to be connected to utilization means to be supplied load currentat a given output potential, an output control circuit adapted to beconnected to means responsive to a control potential for regulating theoutput of the electrical power source, conductor means includingresistor means for carrying load current connected between said inputcircuit and said output power circuit, a first transistor having outputelectrodes connected between said output control circuit and said outputpower circuit and further having 'an input electrode, voltage dividermeans coupled between said conductor means and the reference point andincluding means for maintaining substantially constant currenttherethrough as the voltage at said input circuit varies, :a secondtransistor having input electrodes connected to said voltage dividermeans and said resistor means and further having an output electrodeconnected to the input electrode of said first transistor, said resistormeans providing a voltage to cause changed conduction of said secondtransistor above a given load current for control of said firsttransistor and change of the potential at said output control circuit, athird transistor having input electrodes coupled to said voltage dividermeans and further having an output electrode coupled to said inputelectrode of said first transistor, said voltage divider means includingmeans to cause changed conduction of said third transistor with theoutput voltage above the given output potential for control of saidfirst transistor and change of the potential at said output controlcircuit, and said voltage divider means further including temperatureresponsive means to cause such increased conduction of said thirdtransistor at an it? t output potential higher than the given outputpotential as the ambient temperature decreases.

13. A voltage and current regulator circuit including in combination aninput circuit adapted to be energized with respect to a reference pointby an electrical power source to be regulated, an output power circuitadapted to be connected to utilization means to be supplied load currentat a given output potential, an output control circuit adapted to beconnected to means responsive to a control potential for regulating theoutput of the electrical power source, conductor means includingresistor means for carrying load current connected between said inputcircuit and said output power circuit, a first transistor having outputelectrodes connected between said output control circuit and said outputpower circuit and further having an input electrode, voltage dividermeans coupled between said conductor means and the reference point andincluding means for maintaining substantially constant currenttherethrough as the voltage at said input circuit varies, a secondtransistor having input electrodes connected to said voltage dividermeans and said resistor means and further having an output electrodeconnected to the input electrode of said first transistor, said resistormeans providing a voltage to cause changed conduction of said secondtransistor above a given load current for control of said firsttransistor and change of the potential at said output control circuit,said voltage divider means also having temperature responsive resistormeans for establishing a bias on said second transistor which changeswith temperature to compensate for conduction characteristic changes insaid second transistor, a third transistor having input electrodescoupled to said voltage divider means and further having an outputelectrode coupled to said input electrode of said first transistor, saidvoltage divider means including means to cause changed conduction ofsaid third transistor with the output voltage above the given outputpotential for control of said first transistor and change of thepotential at said output control circuit.

14. A regulator circuit for limiting the voltage and current of avehicular generator system including control means responsive to aregulating potential for controlling the output of the generator systemand output means for supplying charging current to a storage battery,said regulator circuit including in combination, conductor means forinterconnecting the output means of the generator system and the batteryto supply output current at a potential with respect to a referencepoint, a first transistor having output electrodes coupled to theconductor means and adapted to be connected to the control means andhaving an input electrode, said conductor means including resistor meansfor carrying load current and means to prevent conduction from thebattery into said regulator circuit, voltage divider means coupledbetween said conductor means and the reference point and including meansfor maintaining substantially constant current therethrough as thevoltage at the output means of the generator system varies, a secondtransistor having input electrodes connected to said voltage dividermeans and said resistor means and further having an output electrodeconnected to the input electrode of said first transistor, said resistormeans providing a voltage to cause changed conduction of said secondtransistor above a given charging current for control of said firsttransistor and change of the potential at said output electrode of saidfirst transistor, a third transistor having input electrodes coupled tosaid voltage divider means and further having an output electrodecoupled to said input electrode of said first transistor, said voltagedivider means including means to cause changed conduction of said firsttransistor with the voltage output at the output means of the generatorsystem above a given value for control of said first transistor andchange of the potential at said output electrode thereof.

15. A regulator circuit for limiting the voltage and current of avehicular generator system including control means responsive to aregulating potential for controlling the output of the generator systemand output means for supplying charging current to a storage battery,said regulator circuit including in combination, conductor means forinterconnecting the output means of the generator system and the batteryto supply output current at a potential with respect to a referencepoint, a first transistor having output electrodes coupled to saidconductor means and adapted to be connected to the control means andhaving an input electrode, said conductor means including resistor meansfor carrying load current and diode means to prevent conduction from thebattery into said regulator circuit, voltage divider means coupledbetween said conductor means and the reference point and including meansfor maintaining substantially constant current therethrough as thevoltage at the output means of the generator system varies, a secondtransistor having input electrodes connected to said voltage dividermeans and said resistor means and further having an output electrodeconnected to the input electrode of said first transistor, said resistormeans providing a voltage to cause changed conduction of said secondtransistor at a given charging current for control of said firsttransistor and change of the potential at said output electrode of saidfirst transistor, a third transistor having input electrodes coupled tosaid voltage divider means and further having an output electrodecoupled to said input electrode of said first transistor, said voltagedivider means including means to cause changed conduction of said firsttransistor with the voltage output at the output means of the generatorsystem above a given value for control of said first transistor andchange of the potential at said output electrode thereof, and circuitmeans for supplying alternating current to said diode means forrectification thereof and charging of the storage battery.

16. A regulator circuit for limiting the voltage and current of avehicular generator system including a control winding responsive to aregulating current therethrough for controlling the output of thegenerator system and output means for supplying charging current to astorage battery, said regulator circuit including in combination,conductor means for interconnecting the output means of the generatorsystem and the battery to supply output current at a potential withrespect to a reference point, a first transistor having input electrodescoupled between said conductor means and the reference point and anoutput electrode adapted to be connected in series with the con-trolwinding to supply regulating current thereto, said conductor meansincluding a first resistor for carrying output current and a diode poledto prevent conduction from the battery into said regulator circuit,voltage divider means coupled between said conductor means and thereference point, said voltage divider means including a first portionhaving a second resistor coupled to said first resistor and a ballasttube for maintaining substantially constant current through said secondresistor as the voltage output at the output means of the generatorsystem varies, a second transistor having input electrodes connected tosaid first and second resistors and further having an output electrodeconnected to an input electrode of said first transistor, the values ofsaid first and second resistors being selected to permit increasedconduction of said second transistor above a given output current forregulation of said first transistor and reduction of the regulatingcurrent in the control winding, said voltage divider means furtherhaving a second portion including a series connected Zener diode and athird resistor, a third transistor having input electrodes coupledacross said third resistor and further having an output electrodecoupled to an input electrode of said first transistor, the constants ofsaid voltage divider means including the second portion thereof beingselected to cause increased conduction of said third transistor with thevoltage of the generator system above a predetermined value for 12 aregulation of said first transistor and reduction of the regulatingcurrent in the control winding.

17. A regulator circuit for limiting the voltage and current of avehicular generator system including a control winding responsive to aregulating current there-through for controlling the output of thegenerator system and output means for supp-lying charging current to astorage battery, said regulator circuit including in combination,conductor means for interconnecting the output means of the generatorsystem and the battery to supply output current at a potential withrespect to a reference point, said conductor means including a firstresistor for carrying output current and switch means and a diode poledto prevent conduction from the battery into said regulator circuit, afirst transistor having output electrodes adapted to be connected inseries with the control winding and said conductor means to supplyregulating current thereto and further having an input electrode,voltage divider means coupled between said conductor means and thereference point, said voltage divider means including means formaintaining substantially constant current therethrough as the voltageoutput at the output means of the generator system varies, a secondtransistor having input electrodes connected to said voltage dividermeans and further having an output electrode connected to the inputelectrode of said first transistor, said voltage divider means includingmeans for causing increased conduction of said second transistor above agiven output current for regulation of said first transistor andreduction of the regulating current in the control winding, a thirdtransistor having input electrodes coupled to said voltage divider meansand further having an output electrode coupled to an input electrode ofsaid first transistor, said voltage divider means including means tocause increased conduction of said third transistor with the voltage ofthe generator system above a predetermined value for a regulation ofsaid first transistor and reduction of the regulating current in thecontrol winding, and transformer means adapted to be energized by analternating current source, said switch means having contacts to couplesaid transformer means through said diode to the battery for chargin thesame.

18. A voltage and current regulator circuit including in combination aninput circuit adapted to be energized with respect to a reference pointby an electrical power source to be regulated, an output circuit adaptedto be connected to utilization means to be supplied load current at agiven output potential, an output control circuit adapted to beconnected to means responsive to a control potential for regulating theoutput of the electrical power source, conductor means including a firstresistor for carrying load current connected between said input circuitand said output power circuit, a first transistor having outputelectrodes connected to said power circuit and to said output controlcircuit and further having an input electrode, voltage divider meanscoupled between said conductor means and the reference point, saidvoltage divider means including a first portion having a second resistorcoupled to said first resistor and a ballast tube for maintainingsubstantially constant current through said second resistor as thevoltage at said input circuit varies, a second transistor having inputelectrodes connected to said first and second resistors and furtherhaving an output electrode connected to the input electrode of saidfirst transistor, the values of said first and second resistors beingselected to permit increased conduction of said second transistor abovea given load current for control of said first transistor and reductionof the potential at said output control circuit, said voltage dividermeans further having a second portion including a series connected Zenerdiode and a third resistor, 21 third transistor having input electrodescoupled across said third resistor 13 thereof being selected to permitincreased conduction of said third transistor with the output voltageabove a predetermined value for control of said first transistor andreduction of the potential at said output control circuit.

19'. A voltage regulator circuit including in combination an inputcircuit adapted to be energized with respect to a reference point by anelectrical power source to be regulated, an output control circuitadapted to be connected to means responsive to a control potential forregulating the output voltage of the electrical power source, a firsttransistor having output electrodes connected to said input circuit andto said output control circuit and further having an input electrode,voltage divider means coupled between said input circuit and thereference point, said voltage divider means having a series connectedzener diode and a resistor, and a second transistor having inputelectrodes coupled to said zener diode and said voltage divider meansand further having an output electrode coupled to said input electrodeof said first transistor, the constants of said voltage divider meansbeing selected to permit increased conduction of said second transistorwith the output voltage above a predetermined value for control of saidfirst transistor and reduction of the potential at said output controlcircuit, said voltage divider means also including a temperatureresponsive resistor for causing such increased conduction of said secondtransistor to occur at output voltages changing with temperature.

20. A voltage and current regulator circuit for a generator systemincluding a control winding responsive to a regulating currenttherethrough for controlling the output of the generator system andoutput means for supplying direct current to a load, said regulatorcircuit including in combination, conductor means for interconnectingthe output means of the generator system and the load to supply loadcurrent at a potential with respect to a reference point, a controltransistor having input electrodes coupled to said conductor means andthe reference point and an output electrode adapted to be connected inseries with the control winding to supply regulating current thereto,said conductor means including a first resistor for carrying loadcurrent, voltage divider means coupled between said conductor means andthe reference point, said voltage divider means including a firstportion having a second resistor coupled to said first resistor and aballast tube for maintaining substantially constant current through saidsecond resistor as the voltage output at the output means of thegenerator system varies, a current regulating transistor having inputelectrodes connected to said first and second resistors and furtherhaving an output electrode connected to an input electrode of saidcontrol transistor, the values of said first and second resistors beingselected to bias said current regulating transistor to a cutoffcondition below a given load current and to permit conduction of saidcurrent regulating transistor above the given load current forregulation of said control transistor and reduction of the regulatingcurrent in the control winding, said voltage divider means furtherhaving a second portion including a series connected zener diode and athird resistor, a voltage regulating transistor having input electrodescoupled across said third resistor and further having an outputelectrode coupled to an input electrode of said control transistor, theconstants of said voltage divider means including the second portionthereof being selected to bias said voltage regulating transistor to acutoff condition with a voltage of the generator system below apredetermined value and to permit conduction of said voltage regulatingtransistor with such voltage above the predetermined value forregulation of said control transistor and reduction of the regulatingcurrent in the control winding.

No references cited.

